Electrode unit and charged particle beam device

Abstract

A high-resolution sample image is acquired by eliminating both of charge over an entire sample (global charge) and charge in a local region irradiated with a primary charged particle beam (local charge). An electrode unit (50) according to the present invention is used in a charged particle beam device. The electrode unit (50) includes a plate electrode disposed facing an insulator sample between an objective lens and the sample, and further includes: a first charge-neutralization charged particle beam source which emits a first charged particle beam to eliminate local charge on the sample; and a second charge-neutralization charged particle beam source (25) which emits a second charged particle beam to eliminate global charge on the sample. A first hole (53) through which a primary charged particle beam passes, and a second hole through which the second charged particle beam is emitted are provided in the plate electrode, and the first and second charge-neutralization charged particle beam sources are disposed at such positions as not to interfere with each other. The charged particle beam emitted from the first charge-neutralization charged particle beam source is introduced in the vicinity of the first hole (53).

Description

TECHNICAL FIELD[0001]The present invention relates to an electrode unit including a plate electrode disposed facing an insulator sample between an objective lens and the sample, and a charged particle beam device having the electrode unit and used for observing the sample by irradiating the sample with a charged particle beam.BACKGROUND ART[0002]Photomasks are a typical insulator to be observed in a charged particle beam device, such as an SEM, a focused ion beam (FIB) device, or a device combining the SEM and the FIB, which uses charged particles (electrons or ions) secondarily emitted from the insulator surface as a signal to visualize or identify the structure or material of the sample surface.[0003]In a photomask, a laminated film of chromium, molybdenum and silicon, as typical conductors, is generally patterned on a glass substrate having a thickness of about 6 mm to block, reflect or transmit light. When the photomask as a sample is irradiated with a charged particle beam, for...

AI Technical Summary

Benefits of technology

[0064]According to the present invention, higher resolution and stable acqui

Problems solved by technology

Moreover, the electric potential of the sample is unstable, and is thus difficult to estimate, so that the electron beam related to an SEM magnification cannot be appropriately controlled.

In the ESEM or the LVSEM, however, there is a problem that resolution is reduced since the primary charged particle beam travels a long distance in the low vacuum, and collides with the gas to be scattered and spread.

There is also a problem that discharge occurs in the low vacuum in a charged particle detector which operates in a high vacuum.

Images